A cross-flow filtration device comprises a retentate plate, a permeate plate, and a membrane sandwiched between the retentate plate and the permeate plate. The retentate plate comprises at least one feed channel extending from a distribution manifold, and at least one drain channel extending from a collection manifold, and a feed channel is fluidly connected to a drain channel via through-holes extending from a first side of the retentate plate, from a feed channel, to an opposing second side of the retentate plate, and through-holes extending from the second side of the retentate plate to the first side of the retentate plate, into a drain channel. One or more of the through-holes extending from the feed channel have a chamfered inlet.